Motor-driven surgical cutting and fastening instrument with tactile position feedback

ABSTRACT

A surgical cutting and fastening instrument is disclosed. According to various embodiments, the instrument includes an end effector comprising an elongate channel, a clamping member pivotably connected to the channel, and a moveable cutting instrument for traversing the channel to cut an object clamped in the end effector by the clamping member when the clamping member is in a clamped position. The instrument may also comprise a main drive shaft assembly for actuating the cutting instrument in the end effector, a gear drive train connected to the main drive shaft assembly, and a motor for actuating the gear drive train. The instrument may also includes a closure trigger and a firing trigger, separate from the closure trigger, for actuating the motor when the firing trigger is retracted. Also, the instrument may comprise a mechanical closure system connected to the closure trigger and to the clamping member for causing the clamping member to pivot to the clamped position when the closure trigger is retracted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application claiming priority under35 U.S.C. §120 to U.S. patent application Ser. No. 13/656,257, entitledMOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILEPOSITION FEEDBACK, filed Oct. 19, 2012, now U.S. Patent ApplicationPublication No. 2013/0126582, which is a continuation applicationclaiming priority under 35 U.S.C. §120 to Ser. No. 13/151,501, entitledMOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILEPOSITION FEEDBACK, filed Jun. 2, 2011, which issued on Oct. 23, 2012 asU.S. Pat. No. 8,292,155, which is a continuation application claimingpriority under 35 U.S.C. §120 to U.S. patent application Ser. No.11/344,024, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENINGINSTRUMENT WITH MECHANICAL CLOSURE SYSTEM, filed Jan. 31, 2006, whichissued on May 29, 2012 as U.S. Pat. No. 8,186,555, the entiredisclosures of which are hereby incorporated by reference herein.

The present application is also related to the following U.S. patentapplications, filed on Jan. 31, 2006, which are incorporated herein byreference:

-   -   MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH USER        FEEDBACK SYSTEM; U.S. patent application Ser. No. 11/343,498,        now U.S. Pat. No. 7,766,210;    -   MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH        LOADING FORCE FEEDBACK; U.S. patent application Ser. No.        11/343,573, now U.S. Pat. No. 7,416,101;    -   MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH        TACTILE POSITION FEEDBACK; U.S. patent application Ser. No.        11/344,035, now U.S. Pat. No. 7,422,139;    -   MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH        ADAPTIVE USER FEEDBACK; U.S. patent application Ser. No.        11/343,447, now U.S. Pat. No. 7,770,775;    -   MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH        ARTICULATABLE END EFFECTOR; U.S. patent application Ser. No.        11/343,562, now U.S. Pat. No. 7,568,603;    -   SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER        LOCKING MECHANISM; U.S. patent application Ser. No. 11/343,321,        now U.S. Patent Application Publication No. 2007/0175955;    -   GEARING SELECTOR FOR A POWERED SURGICAL CUTTING AND FASTENING        STAPLING INSTRUMENT; U.S. patent application Ser. No.        11/343,563, now U.S. Patent Application Publication No.        2007/0175951;    -   SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES; U.S. patent        application Ser. No. 11/343,803, now U.S. Pat. No. 7,845,537;    -   SURGICAL INSTRUMENT HAVING A REMOVABLE BATTERY; U.S. patent        application Ser. No. 11/344,020, U.S. Pat. No. 7,464,846;    -   ELECTRONIC LOCKOUTS AND SURGICAL INSTRUMENT INCLUDING SAME; U.S.        patent application Ser. No. 11/343,439, now U.S. Pat. No.        7,644,848;    -   ENDOSCOPIC SURGICAL INSTRUMENT WITH A HANDLE THAT CAN ARTICULATE        WITH RESPECT TO THE SHAFT; U.S. patent application Ser. No.        11/343,547, now U.S. Pat. No. 7,753,904;    -   ELECTRO-MECHANICAL SURGICAL CUTTING AND FASTENING INSTRUMENT        HAVING A ROTARY FIRING AND CLOSURE SYSTEM WITH PARALLEL CLOSURE        AND ANVIL ALIGNMENT COMPONENTS; U.S. patent application Ser. No.        11/344,021, now U.S. Pat. No. 7,464,849;    -   DISPOSABLE STAPLE CARTRIDGE HAVING AN ANVIL WITH TISSUE LOCATOR        FOR USE WITH A SURGICAL CUTTING AND FASTENING INSTRUMENT AND        MODULAR END EFFECTOR SYSTEM THEREFOR; U.S. patent application        Ser. No. 11/343,546, now U.S. Patent Application Publication No.        2007/0175950; and    -   SURGICAL INSTRUMENT HAVING A FEEDBACK SYSTEM; U.S. patent        application Ser. No. 11/343,545, now U.S. Pat. No. 8,708,213.

BACKGROUND

The present invention generally concerns surgical cutting and fasteninginstruments and, more particularly, motor-driven surgical cutting andfastening instruments.

Endoscopic surgical instruments are often preferred over traditionalopen surgical devices since a smaller incision tends to reduce thepost-operative recovery time and complications. Consequently,significant development has gone into a range of endoscopic surgicalinstruments that are suitable for precise placement of a distal endeffector at a desired surgical site through a cannula of a trocar. Thesedistal end effectors engage the tissue in a number of ways to achieve adiagnostic or therapeutic effect (e.g., endocutter, grasper, cutter,staplers, clip applier, access device, drug/gene therapy deliverydevice, and energy device using ultrasound, RF, laser, etc.).

Known surgical staplers include an end effector that simultaneouslymakes a longitudinal incision in tissue and applies lines of staples onopposing sides of the incision. The end effector includes a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument includes a plurality ofreciprocating wedges which, when driven distally, pass through openingsin the staple cartridge and engage drivers supporting the staples toeffect the firing of the staples toward the anvil.

An example of a surgical stapler suitable for endoscopic applications isdescribed in U.S. Pat. No. 5,465,895, which discloses an endocutter withdistinct closing and firing actions. A clinician using this device isable to close the jaw members upon tissue to position the tissue priorto firing. Once the clinician has determined that the jaw members areproperly gripping tissue, the clinician can then fire the surgicalstapler with a single firing stroke, or multiple firing strokes,depending on the device. Firing the surgical stapler causes severing andstapling the tissue. The simultaneous severing and stapling avoidscomplications that may arise when performing such actions sequentiallywith different surgical tools that respectively only sever and staple.

One specific advantage of being able to close upon tissue before firingis that the clinician is able to verify via an endoscope that thedesired location for the cut has been achieved, including a sufficientamount of tissue has been captured between opposing jaws. Otherwise,opposing jaws may be drawn too close together, especially pinching attheir distal ends, and thus not effectively forming closed staples inthe severed tissue. At the other extreme, an excessive amount of clampedtissue may cause binding and an incomplete firing.

Endoscopic staplers/cutters continue to increase in complexity andfunction with each generation. One of the main reasons for this is thequest for lower force-to-fire (FTF) to a level that all or a greatmajority of surgeons can handle. One known solution to lower FTF it useCO₂ or electrical motors. These devices have not faired much better thantraditional hand-powered devices, but for a different reason. Surgeonstypically prefer to experience proportionate force distribution to thatbeing experienced by the end-effector in the forming the staple toassure them that the cutting/stapling cycle is complete, with the upperlimit within the capabilities of most surgeons (usually around 15-30lbs). They also typically want to maintain control of deploying thestaple and being able to stop at anytime if the forces felt in thehandle of the device feel too great or for some other clinical reason.These user-feedback effects are not suitably realizable in presentmotor-driven endocutters. As a result, there is a general lack ofacceptance by physicians of motor-drive endocutters where thecutting/stapling operation is actuated by merely pressing a button.

SUMMARY

In one general aspect, the present invention is directed to a motorizedsurgical cutting and fastening instrument that provides feedback to theuser regarding the position, force and/or deployment of the endeffector. The instrument, in various embodiments, also allows theoperator to control the end effector, including being able to stopdeployment if so desired. The instrument may include two triggers in itshandle—a closure trigger and a firing trigger—with separate actuationmotions. When an operator of the instrument retracts the closuretrigger, tissue positioned in the end effector may be clamped by the endeffector. Then, when the operator retracts the firing trigger, a motormay power, via a gear drive train, a rotational main drive shaftassembly, which causes a cutting instrument in the end effector tosevere the clamped tissue.

In various embodiments, the instrument may comprise a power assistsystem with loading force feedback and control to reduce the firingforce required to be exerted by the operator in order to complete thecutting operation. In such embodiments, the firing trigger may be gearedinto the gear drive train of the main drive shaft assembly. In that way,the operator may experience feedback regarding the force being appliedto the cutting instrument. That is, the loading force on the firingtrigger may be related to the loading force experienced by the cuttinginstrument. Also in such embodiments, because the firing trigger isgeared into the gear drive train, force applied by the operator may beadded to the force applied to the motor.

According to various embodiments, when the firing trigger is retractedan appropriate amount (e.g., five degrees), an on/off switch may beactuated, which sends a signal to the motor to rotate at a specifiedrate, thus commencing actuation of the drive shaft assembly and endeffector. According to other embodiments, a proportional sensor may beused. The proportional sensor may send a signal to the motor to rotateat a rate proportional to the force applied to the firing trigger by theoperator. In that way, the rotational position of the firing trigger isgenerally proportional to where the cutting instrument is in the endeffector (e.g., fully deployed or fully retracted). Further, theoperator could stop retracting the firing trigger at some point in thestroke to stop the motor, and thereby stop the cutting motion. Inaddition, sensors may be used to detect the beginning of the stroke ofthe end effector (e.g., fully retracted position) and the end of thestroke (e.g., fully deployed position), respectively. Consequently, thesensors may provide an adaptive control system for controlling endeffector deployment that is outside of the closed loop system of themotor, gear drive train, and end effector.

In other embodiments, the firing trigger may not be directly geared intothe gear drive train used to actuate the end effector. In suchembodiments, a second motor may be used to apply forces to the firingtrigger to simulate the deployment of the cutting instrument in the endeffector. The second motor may be controlled based on incrementalrotations of the main drive shaft assembly, which may be measured by arotary encoder. In such embodiment, the position of the rotationalposition of the firing trigger may be related to the position of thecutting instrument in the end effector. Additionally, an on/off switchor a proportional switch may be used to control the main motor (i.e.,the motor that powers the main drive shaft).

In various implementations, the end effector may use a helical drivescrew in the base of the end effector to drive the cutting instrument(e.g., knife). Also, the end effector may include a staple cartridge forstapling the severed tissue. According to other embodiments, other meansfor fastening (or sealing) the severed tissue may be used, including RFenergy and adhesives.

Also, the instrument may include a mechanical closure system. Themechanical closure system may include an elongate channel having aclamping member, such as an anvil, pivotably connected to the channel toclamp tissue positioned in the end effector. The user may activate theclamping action of the end effector by retracting the closer trigger,which, through a mechanical closure system, causes the clamping actionof the end effector. Once the clamping member is locked in place, theoperator may activate the cutting operation by retracting the separatefiring trigger. This may cause the cutting instrument to travellongitudinally along the channel in order to cut tissue clamped by theend effector.

In various implementations, the instrument may include a rotational maindrive shaft assembly for actuating the end effector. Further, the maindrive shaft may comprise an articulating joint such that the endeffector may be articulated. The articulation joint may comprise, forexample, a bevel gear assembly, a universal joint, or a flexible torsioncable capable of transmitting torsion force to the end effector.

Other aspects of the present invention are directed to variousmechanisms for locking the closure trigger to a lower, pistol-gripportion of the handle. Such embodiments free up space in the handledirectly above and behind the triggers for other components of theinstrument, including components of the gear drive train and themechanical closure system.

DRAWINGS

Various embodiments of the present invention are described herein by wayof example in conjunction with the following figures, wherein

FIGS. 1 and 2 are perspective views of a surgical cutting and fasteninginstrument according to various embodiments of the present invention;

FIGS. 3-5 are exploded views of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 6 is a side view of the end effector according to variousembodiments of the present invention;

FIG. 7 is an exploded view of the handle of the instrument according tovarious embodiments of the present invention;

FIGS. 8 and 9 are partial perspective views of the handle according tovarious embodiments of the present invention;

FIG. 10 is a side view of the handle according to various embodiments ofthe present invention;

FIG. 11 is a schematic diagram of a circuit used in the instrumentaccording to various embodiments of the present invention;

FIGS. 12-13 are side views of the handle according to other embodimentsof the present invention;

FIGS. 14-22 illustrate different mechanisms for locking the closuretrigger according to various embodiments of the present invention;

FIGS. 23A-B show a universal joint (“u-joint”) that may be employed atthe articulation point of the instrument according to variousembodiments of the present invention;

FIGS. 24A-B shows a torsion cable that may be employed at thearticulation point of the instrument according to various embodiments ofthe present invention;

FIGS. 25-31 illustrate a surgical cutting and fastening instrument withpower assist according to another embodiment of the present invention;

FIGS. 32-36 illustrate a surgical cutting and fastening instrument withpower assist according to yet another embodiment of the presentinvention;

FIGS. 37-40 illustrate a surgical cutting and fastening instrument withtactile feedback to embodiments of the present invention;

FIGS. 41-42 illustrate a proportional sensor that may be used accordingto various embodiments of the present invention;

FIG. 43 includes a side view of a handle of a surgical instrument thatmay be provided in association with embodiments of the invention;

FIG. 44 illustrates a partially cross-sectional, partially schematicside view of a gear shifting assembly that can be provided in accordancewith embodiments of the invention;

FIG. 45 illustrates a schematic of a planetary gear arrangement that canbe provided in accordance with embodiments of the invention;

FIG. 46 is an enlarged view of a section of FIG. 44;

FIG. 47 includes an exploded view of a gear shifting assembly that canbe provided in accordance with embodiments of the invention;

FIG. 48 includes a partially cross-sectional, partially schematic sideview of a gear shifting assembly that can be provided in accordance withembodiments of the invention;

FIG. 49 is a view of a section taken through FIG. 48; and

FIG. 50 is an enlarged view of a section of FIG. 48.

DETAILED DESCRIPTION

FIGS. 1 and 2 depict a surgical cutting and fastening instrument 10according to various embodiments of the present invention. Theillustrated embodiment is an endoscopic instrument and, in general, theembodiments of the instrument 10 described herein are endoscopicsurgical cutting and fastening instruments. It should be noted, however,that according to other embodiments of the present invention, theinstrument may be a non-endoscopic surgical cutting and fasteninginstrument, such as a laparoscopic instrument.

The surgical instrument 10 depicted in FIGS. 1 and 2 comprises a handle6, a shaft 8, and an articulating end effector 12 pivotally connected tothe shaft 8 at an articulation pivot 14. An articulation control 16 maybe provided adjacent to the handle 6 to effect rotation of the endeffector 12 about the articulation pivot 14. In the illustratedembodiment, the end effector 12 is configured to act as an endocutterfor clamping, severing and stapling tissue, although, in otherembodiments, different types of end effectors may be used, such as endeffectors for other types of surgical devices, such as graspers,cutters, staplers, clip appliers, access devices, drug/gene therapydevices, ultrasound, RF or laser devices, etc.

The handle 6 of the instrument 10 may include a closure trigger 18 and afiring trigger 20 for actuating the end effector 12. It will beappreciated that instruments having end effectors directed to differentsurgical tasks may have different numbers or types of triggers or othersuitable controls for operating the end effector 12. The end effector 12is shown separated from the handle 6 by a preferably elongate shaft 8.In one embodiment, a clinician or operator of the instrument 10 mayarticulate the end effector 12 relative to the shaft 8 by utilizing thearticulation control 16, as described in more detail in U.S. patentapplication Ser. No. 11/329,020, filed Jan. 10, 2006, entitled SURGICALINSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat. No.7,670,334, which is incorporated herein by reference.

The end effector 12 includes in this example, among other things, astaple channel 22 and a pivotally translatable clamping member, such asan anvil 24, which are maintained at a spacing that assures effectivestapling and severing of tissue clamped in the end effector 12. Thehandle 6 includes a pistol grip 26 towards which a closure trigger 18 ispivotally drawn by the clinician to cause clamping or closing of theanvil 24 toward the staple channel 22 of the end effector 12 to therebyclamp tissue positioned between the anvil 24 and channel 22. The firingtrigger 20 is farther outboard of the closure trigger 18. Once theclosure trigger 18 is locked in the closure position as furtherdescribed below, the firing trigger 20 may rotate slightly toward thepistol grip 26 so that it can be reached by the operator using one hand.Then the operator may pivotally draw the firing trigger 20 toward thepistol grip 12 to cause the stapling and severing of clamped tissue inthe end effector 12. In other embodiments, different types of clampingmembers besides the anvil 24 could be used, such as, for example, anopposing jaw, etc.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the handle 6 of aninstrument 10. Thus, the end effector 12 is distal with respect to themore proximal handle 6. It will be further appreciated that, forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

The closure trigger 18 may be actuated first. Once the clinician issatisfied with the positioning of the end effector 12, the clinician maydraw back the closure trigger 18 to its fully closed, locked positionproximate to the pistol grip 26. The firing trigger 20 may then beactuated. The firing trigger 20 returns to the open position (shown inFIGS. 1 and 2) when the clinician removes pressure, as described morefully below. A release button on the handle 6, when depressed mayrelease the locked closure trigger 18. The release button may beimplemented in various forms such as, for example, as a slide releasebutton 160 shown in FIG. 14, and/or button 172 shown in FIG. 16.

FIG. 3 is an exploded view of the end effector 12 according to variousembodiments. As shown in the illustrated embodiment, the end effector 12may include, in addition to the previously-mentioned channel 22 andanvil 24, a cutting instrument 32, a sled 33, a staple cartridge 34 thatis removably seated in the channel 22, and a helical screw shaft 36. Thecutting instrument 32 may be, for example, a knife. The anvil 24 may bepivotably opened and closed at a pivot point 25 connected to theproximate end of the channel 22. The anvil 24 may also include a tab 27at its proximate end that is inserted into a component of the mechanicalclosure system (described further below) to open and close the anvil 24.When the closure trigger 18 is actuated, that is, drawn in by a user ofthe instrument 10, the anvil 24 may pivot about the pivot point 25 intothe clamped or closed position. If clamping of the end effector 12 issatisfactory, the operator may actuate the firing trigger 20, which, asexplained in more detail below, causes the knife 32 and sled 33 totravel longitudinally along the channel 22, thereby cutting tissueclamped within the end effector 12. The movement of the sled 33 alongthe channel 22 causes the staples of the staple cartridge 34 to bedriven through the severed tissue and against the closed anvil 24, whichturns the staples to fasten the severed tissue. In various embodiments,the sled 33 may be an integral component of the cartridge 34. U.S. Pat.No. 6,978,921, entitled SURGICAL STAPLING INSTRUMENT INCORPORATING ANE-BEAM FIRING MECHANISM, which is incorporated herein by reference,provides more details about such two-stroke cutting and fasteninginstruments. The sled 33 may be part of the cartridge 34, such that whenthe knife 32 retracts following the cutting operation, the sled 33 doesnot retract.

It should be noted that although the embodiments of the instrument 10described herein employ an end effector 12 that staples the severedtissue, in other embodiments different techniques for fastening orsealing the severed tissue may be used. For example, end effectors thatuse RF energy or adhesives to fasten the severed tissue may also beused. U.S. Pat. No. 5,709,680 entitled ELECTROSURGICAL HEMOSTATICDEVICE, and U.S. Pat. No. 5,688,270 entitled ELECTROSURGICAL HEMOSTATICDEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, which are incorporatedherein by reference, disclose an endoscopic cutting instrument that usesRF energy to seal the severed tissue. U.S. patent application Ser. No.11/267,811, now U.S. Pat. No. 7,673,783, and U.S. patent applicationSer. No. 11/267,383, now U.S. Pat. No. 7,607,557, which are alsoincorporated herein by reference, disclose an endoscopic cuttinginstrument that uses adhesives to fasten the severed tissue.Accordingly, although the description herein refers to cutting/staplingoperations and the like below, it should be recognized that this is anexemplary embodiment and is not meant to be limiting. Othertissue-fastening techniques may also be used.

FIGS. 4 and 5 are exploded views and FIG. 6 is a side view of the endeffector 12 and shaft 8 according to various embodiments. As shown inthe illustrated embodiment, the shaft 8 may include a proximate closuretube 40 and a distal closure tube 42 pivotably linked by a pivot links44. The distal closure tube 42 includes an opening 45 into which the tab27 on the anvil 24 is inserted in order to open and close the anvil 24,as further described below. Disposed inside the closure tubes 40, 42 maybe a proximate spine tube 46. Disposed inside the proximate spine tube46 may be a main rotational (or proximate) drive shaft 48 thatcommunicates with a secondary (or distal) drive shaft 50 via a bevelgear assembly 52. The secondary drive shaft 50 is connected to a drivegear 54 that engages a proximate drive gear 56 of the helical screwshaft 36. The vertical bevel gear 52 b may sit and pivot in an opening57 in the distal end of the proximate spine tube 46. A distal spine tube58 may be used to enclose the secondary drive shaft 50 and the drivegears 54, 56. Collectively, the main drive shaft 48, the secondary driveshaft 50, and the articulation assembly (e.g., the bevel gear assembly52 a-c) are sometimes referred to herein as the “main drive shaftassembly.”

A bearing 38, positioned at a distal end of the staple channel 22,receives the helical drive screw 36, allowing the helical drive screw 36to freely rotate with respect to the channel 22. The helical screw shaft36 may interface a threaded opening (not shown) of the knife 32 suchthat rotation of the shaft 36 causes the knife 32 to translate distallyor proximately (depending on the direction of the rotation) through thestaple channel 22. Accordingly, when the main drive shaft 48 is causedto rotate by actuation of the firing trigger 20 (as explained in moredetail below), the bevel gear assembly 52 a-c causes the secondary driveshaft 50 to rotate, which in turn, because of the engagement of thedrive gears 54, 56, causes the helical screw shaft 36 to rotate, whichcauses the knife driving member 32 to travel longitudinally along thechannel 22 to cut any tissue clamped within the end effector. The sled33 may be made of, for example, plastic, and may have a sloped distalsurface. As the sled 33 traverse the channel 22, the sloped forwardsurface may push up or drive the staples in the staple cartridge throughthe clamped tissue and against the anvil 24. The anvil 24 turns thestaples, thereby stapling the severed tissue. When the knife 32 isretracted, the knife 32 and sled 33 may become disengaged, therebyleaving the sled 33 at the distal end of the channel 22.

As described above, because of the lack of user feedback for thecutting/stapling operation, there is a general lack of acceptance amongphysicians of motor-driven endocutters where the cutting/staplingoperation is actuated by merely pressing a button. In contrast,embodiments of the present invention provide a motor-driven endocutterwith user-feedback of the deployment, force, and/or position of thecutting instrument in the end effector.

FIGS. 7-10 illustrate an exemplary embodiment of a motor-drivenendocutter, and in particular the handle thereof, that providesuser-feedback regarding the deployment and loading force of the cuttinginstrument in the end effector. In addition, the embodiment may usepower provided by the user in retracting the firing trigger 20 to powerthe device (a so-called “power assist” mode). As shown in theillustrated embodiment, the handle 6 includes exterior lower side pieces59, 60 and exterior upper side pieces 61, 62 that fit together to form,in general, the exterior of the handle 6. A battery 64, such as a Li ionbattery, may be provided in the pistol grip portion 26 of the handle 6.The battery 64 powers a motor 65 disposed in an upper portion of thepistol grip portion 26 of the handle 6. According to variousembodiments, the motor 65 may be a DC brushed driving motor having amaximum rotation of, approximately, 5000 RPM. The motor 64 may drive a90° bevel gear assembly 66 comprising a first bevel gear 68 and a secondbevel gear 70. The bevel gear assembly 66 may drive a planetary gearassembly 72. The planetary gear assembly 72 may include a pinion gear 74connected to a drive shaft 76. The pinion gear 74 may drive a matingring gear 78 that drives a helical gear drum 80 via a drive shaft 82. Aring 84 may be threaded on the helical gear drum 80. Thus, when themotor 65 rotates, the ring 84 is caused to travel along the helical geardrum 80 by means of the interposed bevel gear assembly 66, planetarygear assembly 72 and ring gear 78.

The handle 6 may also include a run motor sensor 110 in communicationwith the firing trigger 20 to detect when the firing trigger 20 has beendrawn in (or “closed”) toward the pistol grip portion 26 of the handle 6by the operator to thereby actuate the cutting/stapling operation by theend effector 12. The sensor 110 may be a proportional sensor such as,for example, a rheostat or variable resistor. When the firing trigger 20is drawn in, the sensor 110 detects the movement, and sends anelectrical signal indicative of the voltage (or power) to be supplied tothe motor 65. When the sensor 110 is a variable resistor or the like,the rotation of the motor 65 may be generally proportional to the amountof movement of the firing trigger 20. That is, if the operator onlydraws or closes the firing trigger 20 in a little bit, the rotation ofthe motor 65 is relatively low. When the firing trigger 20 is fullydrawn in (or in the fully closed position), the rotation of the motor 65is at its maximum. In other words, the harder the user pulls on thefiring trigger 20, the more voltage is applied to the motor 65, causinggreater rates of rotation.

The handle 6 may include a middle handle piece 104 adjacent to the upperportion of the firing trigger 20. The handle 6 also may comprise a biasspring 112 connected between posts on the middle handle piece 104 andthe firing trigger 20. The bias spring 112 may bias the firing trigger20 to its fully open position. In that way, when the operator releasesthe firing trigger 20, the bias spring 112 will pull the firing trigger20 to its open position, thereby removing actuation of the sensor 110,thereby stopping rotation of the motor 65. Moreover, by virtue of thebias spring 112, any time a user closes the firing trigger 20, the userwill experience resistance to the closing operation, thereby providingthe user with feedback as to the amount of rotation exerted by the motor65. Further, the operator could stop retracting the firing trigger 20 tothereby remove force from the sensor 100, to thereby stop the motor 65.As such, the user may stop the deployment of the end effector 12,thereby providing a measure of control of the cutting/fasteningoperation to the operator.

The distal end of the helical gear drum 80 includes a distal drive shaft120 that drives a ring gear 122, which mates with a pinion gear 124. Thepinion gear 124 is connected to the main drive shaft 48 of the maindrive shaft assembly. In that way, rotation of the motor 65 causes themain drive shaft assembly to rotate, which causes actuation of the endeffector 12, as described above.

The ring 84 threaded on the helical gear drum 80 may include a post 86that is disposed within a slot 88 of a slotted arm 90. The slotted arm90 has an opening 92 its opposite end 94 that receives a pivot pin 96that is connected between the handle exterior side pieces 59, 60. Thepivot pin 96 is also disposed through an opening 100 in the firingtrigger 20 and an opening 102 in the middle handle piece 104.

In addition, the handle 6 may include a reverse motor (or end-of-strokesensor) 130 and a stop motor (or beginning-of-stroke) sensor 142. Invarious embodiments, the reverse motor sensor 130 may be a limit switchlocated at the distal end of the helical gear drum 80 such that the ring84 threaded on the helical gear drum 80 contacts and trips the reversemotor sensor 130 when the ring 84 reaches the distal end of the helicalgear drum 80. The reverse motor sensor 130, when activated, sends asignal to the motor 65 to reverse its rotation direction, therebywithdrawing the knife 32 of the end effector 12 following the cuttingoperation.

The stop motor sensor 142 may be, for example, a normally-closed limitswitch. In various embodiments, it may be located at the proximate endof the helical gear drum 80 so that the ring 84 trips the switch 142when the ring 84 reaches the proximate end of the helical gear drum 80.

In operation, when an operator of the instrument 10 pulls back thefiring trigger 20, the sensor 110 detects the deployment of the firingtrigger 20 and sends a signal to the motor 65 to cause forward rotationof the motor 65 at, for example, a rate proportional to how hard theoperator pulls back the firing trigger 20. The forward rotation of themotor 65 in turn causes the ring gear 78 at the distal end of theplanetary gear assembly 72 to rotate, thereby causing the helical geardrum 80 to rotate, causing the ring 84 threaded on the helical gear drum80 to travel distally along the helical gear drum 80. The rotation ofthe helical gear drum 80 also drives the main drive shaft assembly asdescribed above, which in turn causes deployment of the knife 32 in theend effector 12. That is, the knife 32 and sled 33 are caused totraverse the channel 22 longitudinally, thereby cutting tissue clampedin the end effector 12. Also, the stapling operation of the end effector12 is caused to happen in embodiments where a stapling-type end effectoris used.

By the time the cutting/stapling operation of the end effector 12 iscomplete, the ring 84 on the helical gear drum 80 will have reached thedistal end of the helical gear drum 80, thereby causing the reversemotor sensor 130 to be tripped, which sends a signal to the motor 65 tocause the motor 65 to reverse its rotation. This in turn causes theknife 32 to retract, and also causes the ring 84 on the helical geardrum 80 to move back to the proximate end of the helical gear drum 80.

The middle handle piece 104 includes a backside shoulder 106 thatengages the slotted arm 90 as best shown in FIGS. 8 and 9. The middlehandle piece 104 also has a forward motion stop 107 that engages thefiring trigger 20. The movement of the slotted arm 90 is controlled, asexplained above, by rotation of the motor 65. When the slotted arm 90rotates CCW as the ring 84 travels from the proximate end of the helicalgear drum 80 to the distal end, the middle handle piece 104 will be freeto rotate CCW. Thus, as the user draws in the firing trigger 20, thefiring trigger 20 will engage the forward motion stop 107 of the middlehandle piece 104, causing the middle handle piece 104 to rotate CCW. Dueto the backside shoulder 106 engaging the slotted arm 90, however, themiddle handle piece 104 will only be able to rotate CCW as far as theslotted arm 90 permits. In that way, if the motor 65 should stoprotating for some reason, the slotted arm 90 will stop rotating, and theuser will not be able to further draw in the firing trigger 20 becausethe middle handle piece 104 will not be free to rotate CCW due to theslotted arm 90.

FIGS. 41 and 42 illustrate two states of a variable sensor that may beused as the run motor sensor 110 according to various embodiments of thepresent invention. The sensor 110 may include a face portion 280, afirst electrode (A) 282, a second electrode (B) 284, and a compressibledielectric material 286 (e.g., EAP) between the electrodes 282, 284. Thesensor 110 may be positioned such that the face portion 280 contacts thefiring trigger 20 when retracted. Accordingly, when the firing trigger20 is retracted, the dielectric material 286 is compressed, as shown inFIG. 42, such that the electrodes 282, 284 are closer together. Sincethe distance “b” between the electrodes 282, 284 is directly related tothe impedance between the electrodes 282, 284, the greater the distancethe more impedance, and the closer the distance the less impedance. Inthat way, the amount that the dielectric 286 is compressed due toretraction of the firing trigger 20 (denoted as force “F” in FIG. 42) isproportional to the impedance between the electrodes 282, 284, which canbe used to proportionally control the motor 65.

Components of an exemplary closure system for closing (or clamping) theanvil 24 of the end effector 12 by retracting the closure trigger 18 arealso shown in FIGS. 7-10. In the illustrated embodiment, the closuresystem includes a yoke 250 connected to the closure trigger 18 by a pin251 that is inserted through aligned openings in both the closuretrigger 18 and the yoke 250. A pivot pin 252, about which the closuretrigger 18 pivots, is inserted through another opening in the closuretrigger 18 which is offset from where the pin 251 is inserted throughthe closure trigger 18. Thus, retraction of the closure trigger 18causes the upper part of the closure trigger 18, to which the yoke 250is attached via the pin 251, to rotate CCW. The distal end of the yoke250 is connected, via a pin 254, to a first closure bracket 256. Thefirst closure bracket 256 connects to a second closure bracket 258.Collectively, the closure brackets 256, 258 define an opening in whichthe proximate end of the proximate closure tube 40 (see FIG. 4) isseated and held such that longitudinal movement of the closure brackets256, 258 causes longitudinal motion by the proximate closure tube 40.The instrument 10 also includes a closure rod 260 disposed inside theproximate closure tube 40. The closure rod 260 may include a window 261into which a post 263 on one of the handle exterior pieces, such asexterior lower side piece 59 in the illustrated embodiment, is disposedto fixedly connect the closure rod 260 to the handle 6. In that way, theproximate closure tube 40 is capable of moving longitudinally relativeto the closure rod 260. The closure rod 260 may also include a distalcollar 267 that fits into a cavity 269 in proximate spine tube 46 and isretained therein by a cap 271 (see FIG. 4).

In operation, when the yoke 250 rotates due to retraction of the closuretrigger 18, the closure brackets 256, 258 cause the proximate closuretube 40 to move distally (i.e., away from the handle end of theinstrument 10), which causes the distal closure tube 42 to movedistally, which causes the anvil 24 to rotate about the pivot point 25into the clamped or closed position. When the closure trigger 18 isunlocked from the locked position, the proximate closure tube 40 iscaused to slide proximately, which causes the distal closure tube 42 toslide proximately, which, by virtue of the tab 27 being inserted in thewindow 45 of the distal closure tube 42, causes the anvil 24 to pivotabout the pivot point 25 into the open or unclamped position. In thatway, by retracting and locking the closure trigger 18, an operator mayclamp tissue between the anvil 24 and channel 22, and may unclamp thetissue following the cutting/stapling operation by unlocking the closuretrigger 20 from the locked position.

FIG. 11 is a schematic diagram of an electrical circuit of theinstrument 10 according to various embodiments of the present invention.When an operator initially pulls in the firing trigger 20 after lockingthe closure trigger 18, the sensor 110 is activated, allowing current toflow there through. If the normally-open reverse motor sensor switch 130is open (meaning the end of the end effector stroke has not beenreached), current will flow to a single pole, double throw relay 132.Since the reverse motor sensor switch 130 is not closed, the inductor134 of the relay 132 will not be energized, so the relay 132 will be inits non-energized state. The circuit also includes a cartridge lockoutsensor 136. If the end effector 12 includes a staple cartridge 34, thesensor 136 will be in the closed state, allowing current to flow.Otherwise, if the end effector 12 does not include a staple cartridge34, the sensor 136 will be open, thereby preventing the battery 64 frompowering the motor 65.

When the staple cartridge 34 is present, the sensor 136 is closed, whichenergizes a single pole, single throw relay 138. When the relay 138 isenergized, current flows through the relay 136, through the variableresistor sensor 110, and to the motor 65 via a double pole, double throwrelay 140, thereby powering the motor 65 and allowing it to rotate inthe forward direction.

When the end effector 12 reaches the end of its stroke, the reversemotor sensor 130 will be activated, thereby closing the switch 130 andenergizing the relay 134. This causes the relay 134 to assume itsenergized state (not shown in FIG. 13), which causes current to bypassthe cartridge lockout sensor 136 and variable resistor 110, and insteadcauses current to flow to both the normally-closed double pole, doublethrow relay 142 and back to the motor 65, but in a manner, via the relay140, that causes the motor 65 to reverse its rotational direction.

Because the stop motor sensor switch 142 is normally-closed, currentwill flow back to the relay 134 to keep it closed until the switch 142opens. When the knife 32 is fully retracted, the stop motor sensorswitch 142 is activated, causing the switch 142 to open, therebyremoving power from the motor 65.

In other embodiments, rather than a proportional-type sensor 110, anon-off type sensor could be used. In such embodiments, the rate ofrotation of the motor 65 would not be proportional to the force appliedby the operator. Rather, the motor 65 would generally rotate at aconstant rate. But the operator would still experience force feedbackbecause the firing trigger 20 is geared into the gear drive train.

FIG. 12 is a side-view of the handle 6 of a power-assist motorizedendocutter according to another embodiment. The embodiment of FIG. 12 issimilar to that of FIGS. 7-10 except that in the embodiment of FIG. 12,there is not slotted arm connected to the ring 84 threaded on thehelical gear drum 80. Instead, in the embodiment of FIG. 12, the ring 84includes a sensor portion 114 that moves with the ring 84 as the ring 84advances down (and back) on the helical gear drum 80. The sensor portion114 includes a notch 116. The reverse motor sensor 130 may be located atthe distal end of the notch 116 and the stop motor sensor 142 may belocated at the proximate end of the notch 116. As the ring 84 moves downthe helical gear drum 80 (and back), the sensor portion 114 moves withit. Further, as shown in FIG. 12, the middle piece 104 may have an arm118 that extends into the notch 12.

In operation, as an operator of the instrument 10 retracts in the firingtrigger 20 toward the pistol grip 26, the run motor sensor 110 detectsthe motion and sends a signal to power the motor 65, which causes, amongother things, the helical gear drum 80 to rotate. As the helical geardrum 80 rotates, the ring 84 threaded on the helical gear drum 80advances (or retracts, depending on the rotation). Also, due to thepulling in of the firing trigger 20, the middle piece 104 is caused torotate CCW with the firing trigger 20 due to the forward motion stop 107that engages the firing trigger 20. The CCW rotation of the middle piece104 cause the arm 118 to rotate CCW with the sensor portion 114 of thering 84 such that the arm 118 stays disposed in the notch 116. When thering 84 reaches the distal end of the helical gear drum 80, the arm 118will contact and thereby trip the reverse motor sensor 130. Similarly,when the ring 84 reaches the proximate end of the helical gear drum 80,the arm will contact and thereby trip the stop motor sensor 142. Suchactions may reverse and stop the motor 65, respectively, as describedabove.

FIG. 13 is a side-view of the handle 6 of a power-assist motorizedendocutter according to another embodiment. The embodiment of FIG. 13 issimilar to that of FIGS. 7-10 except that in the embodiment of FIG. 13,there is no slot in the arm 90. Instead, the ring 84 threaded on thehelical gear drum 80 includes a vertical channel 126. Instead of a slot,the arm 90 includes a post 128 that is disposed in the channel 126. Asthe helical gear drum 80 rotates, the ring 84 threaded on the helicalgear drum 80 advances (or retracts, depending on the rotation). The arm90 rotates CCW as the ring 84 advances due to the post 128 beingdisposed in the channel 126, as shown in FIG. 13.

As mentioned above, in using a two-stroke motorized instrument, theoperator first pulls back and locks the closure trigger 18. FIGS. 14 and15 show one embodiment of a way to lock the closure trigger 18 to thepistol grip portion 26 of the handle 6. In the illustrated embodiment,the pistol grip portion 26 includes a hook 150 that is biased to rotateCCW about a pivot point 151 by a torsion spring 152. Also, the closuretrigger 18 includes a closure bar 154. As the operator draws in theclosure trigger 18, the closure bar 154 engages a sloped portion 156 ofthe hook 150, thereby rotating the hook 150 upward (or CW in FIGS.12-13) until the closure bar 154 completely passes the sloped portion156 passes into a recessed notch 158 of the hook 150, which locks theclosure trigger 18 in place. The operator may release the closuretrigger 18 by pushing down on a slide button release 160 on the back oropposite side of the pistol grip portion 26. Pushing down the slidebutton release 160 rotates the hook 150 CW such that the closure bar 154is released from the recessed notch 158.

FIG. 16 shows another closure trigger locking mechanism according tovarious embodiments. In the embodiment of FIG. 16, the closure trigger18 includes a wedge 160 having an arrow-head portion 161. The arrow-headportion 161 is biased downward (or CW) by a leaf spring 162. The wedge160 and leaf spring 162 may be made from, for example, molded plastic.When the closure trigger 18 is retracted, the arrow-head portion 161 isinserted through an opening 164 in the pistol grip portion 26 of thehandle 6. A lower chamfered surface 166 of the arrow-head portion 161engages a lower sidewall 168 of the opening 164, forcing the arrow-headportion 161 to rotate CCW. Eventually the lower chamfered surface 166fully passes the lower sidewall 168, removing the CCW force on thearrow-head portion 161, causing the lower sidewall 168 to slip into alocked position in a notch 170 behind the arrow-head portion 161.

To unlock the closure trigger 18, a user presses down on a button 172 onthe opposite side of the closure trigger 18, causing the arrow-headportion 161 to rotate CCW and allowing the arrow-head portion 161 toslide out of the opening 164.

FIGS. 17-22 show a closure trigger locking mechanism according toanother embodiment. As shown in this embodiment, the closure trigger 18includes a flexible longitudinal arm 176 that includes a lateral pin 178extending therefrom. The arm 176 and pin 178 may be made from moldedplastic, for example. The pistol grip portion 26 of the handle 6includes an opening 180 with a laterally extending wedge 182 disposedtherein. When the closure trigger 18 is retracted, the pin 178 engagesthe wedge 182, and the pin 178 is forced downward (i.e., the arm 176 isrotated CW) by the lower surface 184 of the wedge 182, as shown in FIGS.17 and 18. When the pin 178 fully passes the lower surface 184, the CWforce on the arm 176 is removed, and the pin 178 is rotated CCW suchthat the pin 178 comes to rest in a notch 186 behind the wedge 182, asshown in FIG. 19, thereby locking the closure trigger 18. The pin 178 isfurther held in place in the locked position by a flexible stop 188extending from the wedge 184.

To unlock the closure trigger 18, the operator may further squeeze theclosure trigger 18, causing the pin 178 to engage a sloped backwall 190of the opening 180, forcing the pin 178 upward past the flexible stop188, as shown in FIGS. 20 and 21. The pin 178 is then free to travel outan upper channel 192 in the opening 180 such that the closure trigger 18is no longer locked to the pistol grip portion 26, as shown in FIG. 22.

FIGS. 23A-B show a universal joint (“u-joint”) 195. The second piece195-2 of the u-joint 195 rotates in a horizontal plane in which thefirst piece 195-1 lies. FIG. 23A shows the u-joint 195 in a linear(180°) orientation and FIG. 23B shows the u-joint 195 at approximately a150° orientation. The u-joint 195 may be used instead of the bevel gears52 a-c (see FIG. 4, for example) at the articulation point 14 of themain drive shaft assembly to articulate the end effector 12. FIGS. 24A-Bshow a torsion cable 197 that may be used in lieu of both the bevelgears 52 a-c and the u-joint 195 to realize articulation of the endeffector 12.

FIGS. 25-31 illustrate another embodiment of a motorized, two-strokesurgical cutting and fastening instrument 10 with power assist accordingto another embodiment of the present invention. The embodiment of FIGS.25-31 is similar to that of FIGS. 6-10 except that instead of thehelical gear drum 80, the embodiment of FIGS. 23-28 includes analternative gear drive assembly. The embodiment of FIGS. 25-31 includesa gear box assembly 200 including a number of gears disposed in a frame201, wherein the gears are connected between the planetary gear 72 andthe pinion gear 124 at the proximate end of the drive shaft 48. Asexplained further below, the gear box assembly 200 provides feedback tothe user via the firing trigger 20 regarding the deployment and loadingforce of the end effector 12. Also, the user may provide power to thesystem via the gear box assembly 200 to assist the deployment of the endeffector 12. In that sense, like the embodiments described above, theembodiment of FIGS. 23-32 is another power assist, motorized instrument10 that provides feedback to the user regarding the loading forceexperienced by the cutting instrument.

In the illustrated embodiment, the firing trigger 20 includes twopieces: a main body portion 202 and a stiffening portion 204. The mainbody portion 202 may be made of plastic, for example, and the stiffeningportion 204 may be made out of a more rigid material, such as metal. Inthe illustrated embodiment, the stiffening portion 204 is adjacent tothe main body portion 202, but according to other embodiments, thestiffening portion 204 could be disposed inside the main body portion202. A pivot pin 209 may be inserted through openings in the firingtrigger pieces 202, 204 and may be the point about which the firingtrigger 20 rotates. In addition, a spring 222 may bias the firingtrigger 20 to rotate in a CCW direction. The spring 222 may have adistal end connected to a pin 224 that is connected to the pieces 202,204 of the firing trigger 20. The proximate end of the spring 222 may beconnected to one of the handle exterior lower side pieces 59, 60.

In the illustrated embodiment, both the main body portion 202 and thestiffening portion 204 includes gear portions 206, 208 (respectively) attheir upper end portions. The gear portions 206, 208 engage a gear inthe gear box assembly 200, as explained below, to drive the main driveshaft assembly and to provide feedback to the user regarding thedeployment of the end effector 12.

The gear box assembly 200 may include as shown, in the illustratedembodiment, six (6) gears. A first gear 210 of the gear box assembly 200engages the gear portions 206, 208 of the firing trigger 20. Inaddition, the first gear 210 engages a smaller second gear 212, thesmaller second gear 212 being coaxial with a large third gear 214. Thethird gear 214 engages a smaller fourth gear 216, the smaller fourthgear being coaxial with a fifth gear 218. The fifth gear 218 is a 90°bevel gear that engages a mating 90° bevel gear 220 (best shown in FIG.31) that is connected to the pinion gear 124 that drives the main driveshaft 48.

In operation, when the user retracts the firing trigger 20, a run motorsensor (not shown) is activated, which may provide a signal to the motor65 to rotate at a rate proportional to the extent or force with whichthe operator is retracting the firing trigger 20. This causes the motor65 to rotate at a speed proportional to the signal from the sensor. Thesensor is not shown for this embodiment, but it could be similar to therun motor sensor 110 described above. The sensor could be located in thehandle 6 such that it is depressed when the firing trigger 20 isretracted. Also, instead of a proportional-type sensor, an on/off typesensor may be used.

Rotation of the motor 65 causes the bevel gears 66, 70 to rotate, whichcauses the planetary gear 72 to rotate, which causes, via the driveshaft 76, the ring gear 122 to rotate. The ring gear 122 meshes with thepinion gear 124, which is connected to the main drive shaft 48. Thus,rotation of the pinion gear 124 drives the main drive shaft 48, whichcauses actuation of the cutting/stapling operation of the end effector12.

Forward rotation of the pinion gear 124 in turn causes the bevel gear220 to rotate, which causes, by way of the rest of the gears of the gearbox assembly 200, the first gear 210 to rotate. The first gear 210engages the gear portions 206, 208 of the firing trigger 20, therebycausing the firing trigger 20 to rotate CCW when the motor 65 providesforward drive for the end effector 12 (and to rotate CCW when the motor65 rotates in reverse to retract the end effector 12). In that way, theuser experiences feedback regarding loading force and deployment of theend effector 12 by way of the user's grip on the firing trigger 20.Thus, when the user retracts the firing trigger 20, the operator willexperience a resistance related to the load force experienced by the endeffector 12. Similarly, when the operator releases the firing trigger 20after the cutting/stapling operation so that it can return to itsoriginal position, the user will experience a CW rotation force from thefiring trigger 20 that is generally proportional to the reverse speed ofthe motor 65.

It should also be noted that in this embodiment the user can apply force(either in lieu of or in addition to the force from the motor 65) toactuate the main drive shaft assembly (and hence the cutting/staplingoperation of the end effector 12) through retracting the firing trigger20. That is, retracting the firing trigger 20 causes the gear portions206, 208 to rotate CCW, which causes the gears of the gear box assembly200 to rotate, thereby causing the pinion gear 124 to rotate, whichcauses the main drive shaft 48 to rotate.

Although not shown in FIGS. 25-31, the instrument 10 may further includereverse motor and stop motor sensors. As described above, the reversemotor and stop motor sensors may detect, respectively, the end of thecutting stroke (full deployment of the knife/sled driving member 32) andthe end of retraction operation (full retraction of the knife/sleddriving member 32). A similar circuit to that described above inconnection with FIG. 11 may be used to appropriately power the motor 65.

FIGS. 32-36 illustrate a two-stroke, motorized surgical cutting andfastening instrument 10 with power assist according to anotherembodiment. The embodiment of FIGS. 32-36 is similar to that of FIGS.25-31 except that in the embodiment of FIGS. 32-36, the firing trigger20 includes a lower portion 228 and an upper portion 230. Both portions228, 230 are connected to and pivot about a pivot pin 207 that isdisposed through each portion 228, 230. The upper portion 230 includes agear portion 232 that engages the first gear 210 of the gear boxassembly 200. The spring 222 is connected to the upper portion 230 suchthat the upper portion is biased to rotate in the CW direction. Theupper portion 230 may also include a lower arm 234 that contacts anupper surface of the lower portion 228 of the firing trigger 20 suchthat when the upper portion 230 is caused to rotate CW the lower portion228 also rotates CW, and when the lower portion 228 rotates CCW theupper portion 230 also rotates CCW. Similarly, the lower portion 228includes a rotational stop 238 that engages a lower shoulder of theupper portion 230. In that way, when the upper portion 230 is caused torotate CCW the lower portion 228 also rotates CCW, and when the lowerportion 228 rotates CW the upper portion 230 also rotates CW.

The illustrated embodiment also includes the run motor sensor 110 thatcommunicates a signal to the motor 65 that, in various embodiments, maycause the motor 65 to rotate at a speed proportional to the forceapplied by the operator when retracting the firing trigger 20. Thesensor 110 may be, for example, a rheostat or some other variableresistance sensor, as explained herein. In addition, the instrument 10may include a reverse motor sensor 130 that is tripped or switched whencontacted by a front face 242 of the upper portion 230 of the firingtrigger 20. When activated, the reverse motor sensor 130 sends a signalto the motor 65 to reverse direction. Also, the instrument 10 mayinclude a stop motor sensor 142 that is tripped or actuated whencontacted by the lower portion 228 of the firing trigger 20. Whenactivated, the stop motor sensor 142 sends a signal to stop the reverserotation of the motor 65.

In operation, when an operator retracts the closure trigger 18 into thelocked position, the firing trigger 20 is retracted slightly (throughmechanisms known in the art, including U.S. Pat. No. 6,978,921 and U.S.Pat. No. 6,905,057, which are incorporated herein by reference) so thatthe user can grasp the firing trigger 20 to initiate thecutting/stapling operation, as shown in FIGS. 32 and 33. At that point,as shown in FIG. 33, the gear portion 232 of the upper portion 230 ofthe firing trigger 20 moves into engagement with the first gear 210 ofthe gear box assembly 200. When the operator retracts the firing trigger20, according to various embodiments, the firing trigger 20 may rotate asmall amount, such as five degrees, before tripping the run motor sensor110, as shown in FIG. 34. Activation of the sensor 110 causes the motor65 to forward rotate at a rate proportional to the retraction forceapplied by the operator. The forward rotation of the motor 65 causes, asdescribed above, the main drive shaft 48 to rotate, which causes theknife 32 in the end effector 12 to be deployed (i.e., begin traversingthe channel 22). Rotation of the pinion gear 124, which is connected tothe main drive shaft 48, causes the gears 210-220 in the gear boxassembly 200 to rotate. Since the first gear 210 is in engagement withthe gear portion 232 of the upper portion 230 of the firing trigger 20,the upper portion 232 is caused to rotate CCW, which causes the lowerportion 228 to also rotate CCW.

When the knife 32 is fully deployed (i.e., at the end of the cuttingstroke), the front face 242 of the upper portion 230 trips the reversemotor sensor 130, which sends a signal to the motor 65 to reverserotational directional. This causes the main drive shaft assembly toreverse rotational direction to retract the knife 32. Reverse rotationof the main drive shaft assembly causes the gears 210-220 in the gearbox assembly to reverse direction, which causes the upper portion 230 ofthe firing trigger 20 to rotate CW, which causes the lower portion 228of the firing trigger 20 to rotate CW until the lower portion 228 tripsor actuates the stop motor sensor 142 when the knife 32 is fullyretracted, which causes the motor 65 to stop. In that way, the userexperiences feedback regarding deployment of the end effector 12 by wayof the user's grip on the firing trigger 20. Thus, when the userretracts the firing trigger 20, the operator will experience aresistance related to the deployment of the end effector 12 and, inparticular, to the loading force experienced by the knife 32. Similarly,when the operator releases the firing trigger 20 after thecutting/stapling operation so that it can return to its originalposition, the user will experience a CW rotation force from the firingtrigger 20 that is generally proportional to the reverse speed of themotor 65.

It should also be noted that in this embodiment the user can apply force(either in lieu of or in addition to the force from the motor 65) toactuate the main drive shaft assembly (and hence the cutting/staplingoperation of the end effector 12) through retracting the firing trigger20. That is, retracting the firing trigger 20 causes the gear portion232 of the upper portion 230 to rotate CCW, which causes the gears ofthe gear box assembly 200 to rotate, thereby causing the pinion gear 124to rotate, which causes the main drive shaft assembly to rotate.

The above-described embodiments employed power-assist user feedbacksystems, with or without adaptive control (e.g., using a sensor 110,130, and 142 outside of the closed loop system of the motor, gear drivetrain, and end effector) for a two-stroke, motorized surgical cuttingand fastening instrument. That is, force applied by the user inretracting the firing trigger 20 may be added to the force applied bythe motor 65 by virtue of the firing trigger 20 being geared into(either directly or indirectly) the gear drive train between the motor65 and the main drive shaft 48. In other embodiments of the presentinvention, the user may be provided with tactile feedback regarding theposition of the knife 32 in the end effector, but without having thefiring trigger 20 geared into the gear drive train. FIGS. 37-40illustrate a motorized surgical cutting and fastening instrument withsuch a tactile position feedback system.

In the illustrated embodiment of FIGS. 37-40, the firing trigger 20 mayhave a lower portion 228 and an upper portion 230, similar to theinstrument 10 shown in FIGS. 32-36. Unlike the embodiment of FIGS.32-36, however, the upper portion 230 does not have a gear portion thatmates with part of the gear drive train. Instead, the instrumentincludes a second motor 265 with a threaded rod 266 threaded therein.The threaded rod 266 reciprocates longitudinally in and out of the motor265 as the motor 265 rotates, depending on the direction of rotation.The instrument 10 also includes an encoder 268 that is responsive to therotations of the main drive shaft 48 for translating the incrementalangular motion of the main drive shaft 48 (or other component of themain drive assembly) into a corresponding series of digital signals, forexample. In the illustrated embodiment, the pinion gear 124 includes aproximate drive shaft 270 that connects to the encoder 268.

The instrument 10 also includes a control circuit (not shown), which maybe implemented using a microcontroller or some other type of integratedcircuit, that receives the digital signals from the encoder 268. Basedon the signals from the encoder 268, the control circuit may calculatethe stage of deployment of the knife 32 in the end effector 12. That is,the control circuit can calculate if the knife 32 is fully deployed,fully retracted, or at an intermittent stage. Based on the calculationof the stage of deployment of the end effector 12, the control circuitmay send a signal to the second motor 265 to control its rotation tothereby control the reciprocating movement of the threaded rod 266.

In operation, as shown in FIG. 37, when the closure trigger 18 is notlocked into the clamped position, the firing trigger 20 rotated awayfrom the pistol grip portion 26 of the handle 6 such that the front face242 of the upper portion 230 of the firing trigger 20 is not in contactwith the proximate end of the threaded rod 266. When the operatorretracts the closure trigger 18 and locks it in the clamped position,the firing trigger 20 rotates slightly towards the closure trigger 20 sothat the operator can grasp the firing trigger 20, as shown in FIG. 38.In this position, the front face 242 of the upper portion 230 contactsthe proximate end of the threaded rod 266.

As the user then retracts the firing trigger 20, after an initialrotational amount (e.g., 5 degrees of rotation) the run motor sensor 110may be activated such that, as explained above, the sensor 110 sends asignal to the motor 65 to cause it to rotate at a forward speedproportional to the amount of retraction force applied by the operatorto the firing trigger 20. Forward rotation of the motor 65 causes themain drive shaft 48 to rotate via the gear drive train, which causes theknife 32 and sled 33 to travel down the channel 22 and sever tissueclamped in the end effector 12. The control circuit receives the outputsignals from the encoder 268 regarding the incremental rotations of themain drive shaft assembly and sends a signal to the second motor 265 tocaused the second motor 265 to rotate, which causes the threaded rod 266to retract into the motor 265. This allows the upper portion 230 of thefiring trigger 20 to rotate CCW, which allows the lower portion 228 ofthe firing trigger to also rotate CCW. In that way, because thereciprocating movement of the threaded rod 266 is related to therotations of the main drive shaft assembly, the operator of theinstrument 10, by way of his/her grip on the firing trigger 20,experiences tactile feedback as to the position of the end effector 12.The retraction force applied by the operator, however, does not directlyaffect the drive of the main drive shaft assembly because the firingtrigger 20 is not geared into the gear drive train in this embodiment.

By virtue of tracking the incremental rotations of the main drive shaftassembly via the output signals from the encoder 268, the controlcircuit can calculate when the knife 32 is fully deployed (i.e., fullyextended). At this point, the control circuit may send a signal to themotor 65 to reverse direction to cause retraction of the knife 32. Thereverse direction of the motor 65 causes the rotation of the main driveshaft assembly to reverse direction, which is also detected by theencoder 268. Based on the reverse rotation detected by the encoder 268,the control circuit sends a signal to the second motor 265 to cause itto reverse rotational direction such that the threaded rod 266 starts toextend longitudinally from the motor 265. This motion forces the upperportion 230 of the firing trigger 20 to rotate CW, which causes thelower portion 228 to rotate CW. In that way, the operator may experiencea CW force from the firing trigger 20, which provides feedback to theoperator as to the retraction position of the knife 32 in the endeffector 12. The control circuit can determine when the knife 32 isfully retracted. At this point, the control circuit may send a signal tothe motor 65 to stop rotation.

According to other embodiments, rather than having the control circuitdetermine the position of the knife 32, reverse motor and stop motorsensors may be used, as described above. In addition, rather than usinga proportional sensor 110 to control the rotation of the motor 65, anon/off switch or sensor can be used. In such an embodiment, the operatorwould not be able to control the rate of rotation of the motor 65.Rather, it would rotate at a preprogrammed rate.

With general reference to FIGS. 43 through 50, in various embodiments ofthe invention, a gear shifting assembly 2402 may be employed foroperative interaction with the motor 65, for example, of the surgicalinstrument 10. The gear shifting assembly 2402 can be connected to themotor 65 and to the drive shaft 76 and can be configured to permit auser to adjust mechanical power transferred to the drive shaft 76 fromthe motor 65. As described below in more detail, the gear shiftingassembly 2402 allows for the selective increase or decrease of gearratio for transfer of power developed by the motor 65 of the instrument10. This selective increase/decrease feature can be beneficial for usein association with surgical operations that involve using theinstrument 10 to cut/staple various types and densities of tissue.

With reference to FIGS. 43 through 47, the gear shifting assembly 2402includes a first stage gear assembly 2404 receiving mechanical inputpower from an input shaft 2406 connected to the motor 65. In variousembodiments, the input shaft 2406 may connected directly to the motor65, or power may be transferred from the motor 65 to the input shaft2406 through one or more other components, such as the bevel gearassemblies 66, 70, for example. As shown more particularly in FIG. 45,the first stage gear assembly 1004 may include a sun gear 2404Aintermeshed at least partially with one or more surrounding planet gears2404B, 2404C, 2404D to provide a planetary gear arrangement for thefirst stage gear assembly 2404. During operation of the instrument 10,the sun gear 2404A of the first stage gear assembly 2404 may beconnected to the input shaft 2406 for transferring mechanical inputpower from the motor 65 to cause rotation of the sun gear 2404A. It canbe seen that, as a consequence of the rotation of the sun gear 2404A,each of the planet gears 2404B, 2404C, 2404D, also rotate accordingly.Each of the planet gears 2404B, 2404C, 2404D may be connected throughpins 2404E, 2404F, 2404G (respectively) to transfer mechanical powergenerated by the rotational movement of the sun gear 2404A to a geardisc 2404H of the first stage gear assembly 2404, as shown.

The gear disc 2404H of the first stage gear assembly 2404 may beconnected to an input shaft 2408 which may be connected, in turn, to asecond gear stage assembly 2410. The second stage gear assembly 2410 maybe structured in substantial accordance with the structure andcomponents employed by the first stage gear assembly 2404 (describedabove). The second stage gear assembly 2410 may include a sun gear 2410Aintermeshed at least partially with one or more planet gears, such asplanet gear 2410B, for example, to provide a planetary gear arrangementfor the assembly 2410. The sun gear 2410A of the second stage gearassembly 2410 may be connected to the input shaft 2408 for transferringrotational input power received from the first stage gear assembly 2404.In a fashion similar to the planet gears 2404B, 2404C, 2404D of thefirst stage gear assembly 2404, the planet gears 2410B may be connectedthrough pins 2410C to transfer power generated by the rotationalmovement of the sun gear 2410A to a gear disc 2410D of the second stagegear assembly 2410.

In a first gear setting of the gear shifting assembly 2402, as shown inFIG. 44, the first and second stage gear assemblies 2404, 2410 can becoupled to drive shaft 76 of the instrument 10. It can be appreciated,however, that more or less gear assemblies than the gear assemblies2404, 2410 illustrated, or portions thereof, may be suitably employed inthe instrument 10, depending on the gear ratio or application desiredfor the instrument 10. For example, in certain embodiments, a thirdstage gear assembly could be included in the drive train with an inputshaft connected to the output of the second stage gear assembly 2410.

In various embodiments, a gear coupling assembly 2420 may be connectedto the gear disc 2410D of the second stage gear assembly 2410 through aninput shaft 2422. The gear coupling assembly 2420 may include a sun gear2420A at least partially intermeshed with one or more planet gears, suchas planet gear 2420B. This planetary gear arrangement, including the sungear 2420A and planet gear 2420B, may be abutted by a retainer disc2420C connected through a pin 2420D extending through each of the planetgears 2420B to a collar 2420E. In addition, a thrust bearing 2420F maybe positioned between the sun gear 2420A and the retainer disc 2420C;and a thrust bearing 2420G may be positioned between the sun gear 2420Aand the collar 2420E, to promote secure positioning of the sun gear2420A within the gear coupling assembly 2420.

The sun gear 2420A may include a spline section 2420H which can bestructured to correspondingly intermesh with a spline section 2424formed on the input shaft 2422. In the first gear setting illustrated inFIG. 44, the spline section 2420H of the sun gear 2420A is notintermeshed with the spline section 2424 of the input shaft 2422. It canbe appreciated that the first gear setting provides direct drive fromthe second stage gear assembly 2410 to the retainer disc 2420C of thegear coupling assembly 2420, without operative interaction of the sungear 2420A with the input shaft 2422. In other words, the sun gear 2420Aof the gear coupling assembly 1020 is permitted to freewheel in thefirst gear setting and is not coupled to the drive shaft 76 along withthe first and second stage gear assemblies 2404, 2410. The collar 2420Eincludes a spline section 2420I which can be structured tocorrespondingly intermesh with a spline section 2426 formed on the driveshaft 76. It can be seen that, in the first gear setting, the splinesection 2420I of the collar 2420E intermeshes with the spline section2426 of the drive shaft 76 to transfer mechanical rotational power fromthe collar 2420E to the drive shaft 76. In addition, in the first gearsetting, the spline section 2420I of the collar 2420E maycorrespondingly intermesh with the spline section 2424 on the inputshaft 2422.

In various embodiments, the gear coupling assembly 2420 may be movedfrom or into the first gear setting by use of a gear selector assembly2432. The gear selector assembly 2432 includes a switch 2432A connectedto a yoke 2432B. The switch 2432A may be configured to permit the thumbor finger of a user, for example, to move the gear coupling assembly2420 from or into the first gear setting through its connection to theyoke 2432B. As shown more particularly in FIG. 47, the yoke 2432B may beconnected to the collar 2420E of the gear coupling assembly 2420 bybeing received into a yoke receiving groove 2420J positioned around atleast a portion of the circumference of the collar 2420E. The yoke 2432Bmay include one or more pins 2432C, 2432D extending from the yoke 2432Bthat can be structured to be received into the yoke receiving groove2420J to promote securement of the yoke 2432B therein. As shown in FIG.44, the gear selector assembly 2432 has been activated to put the gearshifting assembly 2402 in the first gear setting position.

With reference to FIGS. 48 through 50, in a second gear setting of thegear shifting assembly 2402, the gear coupling assembly 2420 can beselectively moved distally with respect to the motor 65 to engage orcouple the spline section 2420H of the sun gear 2420A with the splinesection 2424 of the input shaft 2422. The movement of the gear couplingassembly 2420 may be effected by action of the yoke 2432B through itsconnection to the collar 2420E of the gear coupling assembly 2420. Asdescribed above, the action of the yoke 2432B in moving the gearcoupling assembly 2420 between first and second gear settings may beeffected by a user activating the switch 2432A of the gear selectorassembly 2432. It can be seen that the spline section 2420I of thecollar 2420E remains engaged or intermeshed with the spline section 2426formed on the drive shaft 76 in both first and second gear settings totransfer mechanical power through the gear coupling assembly 2420 to thedrive shaft 76.

It can be appreciated that in the first gear setting, only the first andsecond stage gear assemblies 2404, 2410 are operatively involved withthe motor 65 in directly driving the drive shaft 76. The first gearsetting can be used for comparatively lower torque, higher speedapplications of the drive shaft 76, such as for operations involvingcutting/stapling relatively low density tissue, for example. In thesecond gear setting, the planetary gear arrangement of the gear couplingassembly 2420 can be coupled to the drive train to provide comparativelyhigher torque, lower speed action of the drive shaft 76, such as foroperations involving cutting/stapling relatively high density tissue,for example. In general, in various embodiments, the gear shiftingassembly 2402 permits a user to achieve an appropriate blend of torqueand speed for the drive train, depending on the needs of the variousoperations in which the instrument 10 is employed on tissue of differentdensity, thickness, or other characteristics.

The various embodiments of the present invention have been describedabove in connection with cutting-type surgical instruments. It should benoted, however, that in other embodiments, the inventive surgicalinstrument disclosed herein need not be a cutting-type surgicalinstrument. For example, it could be a non-cutting endoscopicinstrument, a grasper, a stapler, a clip applier, an access device, adrug/gene therapy delivery device, an energy device using ultrasound,RF, laser, etc.

Although the present invention has been described herein in connectionwith certain disclosed embodiments, many modifications and variations tothose embodiments may be implemented. For example, different types ofend effectors may be employed. Also, where materials are disclosed forcertain components, other materials may be used. The foregoingdescription and following claims are intended to cover all suchmodification and variations.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

What is claimed is:
 1. A surgical cutting and fastening instrumentcomprising: an end effector comprising a moveable cutting instrument forcutting an object positioned in the end effector; a main drive shaftassembly connected to the end effector; a gear drive train connected tothe main drive shaft assembly; a main motor for actuating the gear drivetrain; a firing trigger for actuating the main motor; and a tactileposition feedback system for applying force to the firing trigger suchthat the position of the firing trigger is related to the position ofthe cutting instrument in the end effector.
 2. The surgical cutting andfastening instrument of claim 1, wherein the tactile position feedbacksystem includes: an encoder for sensing rotation of the main drive shaftassembly; a second motor whose rotations are controlled based on therotations main drive shaft assembly sensed by the encoder; and anactuating member connected to the second motor, wherein the actuatingmember is for applying the force to the firing trigger such thatposition of the firing trigger is related to the position of the cuttinginstrument in the end effector.
 3. The surgical cutting and fasteninginstrument of claim 2, wherein the actuating member includes a threadedrod.
 4. The surgical cutting and fastening instrument of claim 2,further comprising a run motor sensor for sensing retracting of thefiring trigger, wherein, when retraction of the firing trigger is sensedby the run motor sensor, the main motor is signaled to forward rotate tocause cutting of the object positioned in the end effector by thecutting instrument.
 5. The surgical cutting and fastening instrument ofclaim 4, wherein the run motor sensor comprises a proportional switchsuch that the rate of rotation of the main motor is proportional to theretraction force applied to the firing trigger.
 6. The surgical cuttingand fastening instrument of claim 4, wherein the run motor sensorcomprises an on/off switch.
 7. The surgical cutting and fasteninginstrument of claim 4, further comprising a control circuit forreceiving signals from the encoder related to rotation of the main driveshaft assembly and for sending control signals to the second motor basedon the signals received from the encoder.
 8. The surgical cutting andfastening instrument of claim 7, wherein the control circuit is furtherfor: determining, based on the signals received from the encoder, whenthe cutting instrument has completed a cutting stroke; and determining,based on the signals received from the encoder, when the cuttinginstrument has completed retraction.
 9. The surgical cutting andfastening instrument of claim 1, wherein the end effector includes astaple cartridge.
 10. The surgical cutting and fastening instrument ofclaim 1, wherein the end effector includes a helical drive screw, suchthat forward rotation of the helical drive screw causes the cuttinginstrument to undertake the cutting stroke, and reverse rotation of thehelical drive screw causes the cutting instrument to retract.
 11. Thesurgical cutting and fastening instrument of claim 1, wherein the maindrive shaft assembly includes articulation means for articulating theend effector.
 12. The surgical cutting and fastening instrument of claim1, further comprising a closure trigger separate from the firingtrigger, wherein retraction of the closure trigger causes the endeffector to clamp the object positioned in the end effector.
 13. Thesurgical cutting and fastening instrument of claim 12, furthercomprising a locking mechanism for locking the closure trigger to thehandle.
 14. The surgical cutting and fastening instrument of claim 12,further comprising a mechanical closure system for closing the endeffector when the closure trigger is retracted.
 15. The surgical cuttingand fastening instrument of claim 14, wherein the end effectorcomprises: an elongate channel for carrying the cutting instrument; anda clamping member pivotably connected to the elongate channel.
 16. Thesurgical cutting and fastening instrument of claim 15, wherein themechanical closure system includes: a yoke connected to the closuretrigger; a closure bracket connected to the yoke; a closure tubedisposed in the closure bracket and connected to the clamping member,wherein retraction of the closure trigger causes the closure tube tomove longitudinally such that the clamping member pivots to a clampedposition.
 17. A surgical cutting and fastening instrument comprising: anend effector comprising a moveable cutting instrument for cutting anobject positioned in the end effector; a main drive shaft assemblyconnected to the end effector; and a handle connected to the main driveshaft assembly, wherein the handle comprises: a gear drive trainconnected to the main drive shaft assembly; a main motor for actuatingthe gear drive train; a firing trigger for actuating the main motor; anda tactile position feedback system for applying force to the firingtrigger such that position of the firing trigger is related to theposition of the cutting instrument in the end effector; and a run motorsensor for sensing retracting of the firing trigger, wherein, whenretraction of the firing trigger is sensed by the run motor sensor, themain motor is signaled to forward rotate to cause cutting of the objectpositioned in the end effector by the cutting instrument.
 18. Thesurgical cutting and fastening instrument of claim 17, wherein the runmotor sensor comprises a proportional switch such that the rate ofrotation of the main motor is proportional to the retraction forceapplied to the firing trigger.
 19. The surgical cutting and fasteninginstrument of claim 18, wherein the end effector comprises: an elongatechannel for carrying the cutting instrument; and a clamping memberpivotably connected to the elongate channel.
 20. A surgical cutting andfastening instrument comprising: an end effector comprising a moveablecutting instrument for cutting an object positioned in the end effector.a main drive shaft assembly connected to the end effector; and a handleconnected to the main drive shaft assembly, wherein the handlecomprises: a gear drive train connected to the main drive shaftassembly; a main motor for actuating the gear drive train; a firingtrigger for actuating the main motor; and means for applying force tothe firing trigger such that position of the firing trigger is relatedto the position of the cutting instrument in the end effector.